Innovative Seizure of Metal/Metal Oxide Nanoparticles in Water Purification: A Critical Review of Potential Risks.

Water contamination is a worldwide critical issue for the present society to avoid competition and maintain an environmentally friendly scenario. Removal of various pollutants including inorganic and organic compounds from water is a big challenge nowadays. Worldwide attention to promote polluted water and technologies related to its treatment has been adversely increased. The utilization of metal/metal oxide nanoparticles (NPs) for this purpose has gained much attention due to its exceptional properties imparted by reduced size and effective surface area. Moreover, metal/metal oxide NPs-based innovation for improved expulsion productivity is an ingenious area for research and development but the use of such NPs presents some serious risks. Herein, the advanced requisition of NPs for polluted water treatment is highlighted along with the difficulties related to them and their toxic impacts when used as water purifiers. Additionally, the plausible fate of metal/metal oxide NPs incorporated in the water for purification and salient future challenges are deliberated.

Adsorption optimization of lead (II) using Saccharum bengalense as a non-conventional low cost biosorbent: isotherm and thermodynamics modeling.

In the present study a novel biomass, derived from the pulp of Saccharum bengalense, was used as an adsorbent material for the removal of Pb (II) ions from aqueous solution. After 50 minutes contact time, almost 92% lead removal was possible at pH 6.0 under batch test conditions. The experimental data was analyzed using Langmuir, Freundlich, Timken and Dubinin-Radushkevich two parameters isotherm model, three parameters Redlich-Peterson, Sip and Toth models and four parameters Fritz Schlunder isotherm models. Langmuir, Redlich-Peterson and Fritz-Schlunder models were found to be the best fit models. Kinetic studies revealed that the sorption process was well explained with pseudo second-order kinetic model Thermodynamic parameters including free energy change (AG degrees), enthalpy change (AH degrees) and entropy change (AS degrees) have been calculated and reveal the spontaneous, endothermic and feasible nature of the adsorption process. The thermodynamic parameters of activation (deltaG(#), deltaH(#) and deltaS(#)) were calculated from the pseudo-second order rate constant by using the Eyring equation. Results showed that Pb (II) adsorption onto SB is an associated mechanism and the reorientation step is entropy controlled.

Biosorption potentials of a novel green biosorbent Saccharum bengalense containing cellulose as carbohydrate polymer for removal of Ni (II) ions from aqueous solutions.

In this research work, the potential of a novel green material obtained from Saccharum bengalense (SB) plant was investigated for the removal of Ni (II) ions from aqueous solution. Biomaterial SB composed of cellulose macromolecules and was used without any chemical treatment. Batch experiments were performed by considering the effect of contact time, SB concentration, pH of the solution and temperature. Results revealed that ∼87% of Ni was removed from aqueous solution at optimum conditions. Three typical kinetic models namely, pseudo first order, pseudo second order and Elovich equations were applied to interpret the kinetic data. To investigate the rate determining step, the intra-particle diffusion model was applied on the experimental data. The sorption process was well explained with pseudo second-order kinetic model. Adsorption isothermal data was examined by applying classical two parameters (Langmuir, Freundlich, Timken and Dubinin-Radushkevich) and three parameters (Redlich-Peterson, Toth and Sips models) and four parameters Fritz Schlunder Isotherm models. Based on R(2) and χ(2) the equilibrium sorption data was better fitted to Langmuir and Sips isotherm model than any other model. Thermodynamics parameters such as free energy change (ΔG°), enthalpy change (ΔH°) and entropy change (ΔS°) have been calculated respectively, which revealed the spontaneous, endothermic and feasible nature of adsorption process. The results of the present investigation suggest that S. bengalense can be used as an environmentally benign and low cost biomaterial for nickel removal from aqueous solution.